CN207706077U - A kind of temperature difference electricity generation device using boiler back end ductwork fume afterheat - Google Patents

Abstract

The utility model relates to a thermoelectric power generation device utilizing the residual heat of flue gas at the tail of a boiler. The thermoelectric power generation device is vertically placed in the middle of the tail flue at the outlet of the boiler air preheater. The thermoelectric power generation device includes a thermoelectric power generation module, an inverter The thermoelectric generator and the cold source module installed at one end of the thermoelectric power generation module, the thermoelectric power generation module is connected to the inverter through wires; The temperature difference generates electricity, which is sent to the inverter through wires. Compared with the prior art, the utility model has the advantages of large generating power and small occupied space.

Description

A thermoelectric power generation device using the waste heat of the flue gas at the tail of the boiler

technical field

The utility model relates to the field of waste heat utilization for energy saving and consumption reduction, in particular to a thermoelectric power generation device utilizing the waste heat of flue gas at the tail of a boiler.

Background technique

In recent years, countries around the world, especially developed countries, have taken improving energy utilization efficiency as an important goal of energy development strategies. my country has also successively proposed a number of energy-saving and emission-reduction policies. As an important part of the energy structure, the power industry is of great significance to carry out energy conservation and consumption reduction.

Thermal power plant exhaust heat loss is the most important energy loss on the boiler side. For the utilization of boiler flue gas waste heat, various designs and engineering practices have been adopted at home and abroad, all of which adopt the type of flue gas heat exchanger. The heat in the gas is replaced by other media for use. It is called "low temperature economizer", "low pressure economizer", "smoke-water heat exchanger", etc. The principle is the same, except that the layout of the heat exchanger is different from that of the heat exchanger. The heat medium is different:

Figure 1 shows that the waste heat utilization device is arranged before the absorption tower, and condensed water is used to absorb the waste heat of flue gas. Figure 2 shows that the waste heat utilization device is arranged at the tail of the boiler, and condensed water is used to absorb the waste heat of flue gas.

The Chinese patent announcement number is CN204880080U, which discloses a boiler flue gas waste heat recovery system, including: an economizer, a pump body, a first heat exchanger, a second heat exchanger, a heat network water system and a condensate water system. This utility model realizes independent heat exchange between heating network water and condensed water, effectively prevents water quality interference, ensures that the condensed water of the main engine is not polluted, and heats the condensed water partly with the heat absorbed by the low-temperature economizer after the dust collector. Part of the heat network water is heated, and the heat network water is used to absorb heat to reduce the temperature of the flue gas.

Thermoelectric power generation is a green power generation technology that converts thermal energy generated by the temperature difference between high temperature and low temperature into electrical energy based on the Seebeck effect.

In addition, Chinese patent applications with Chinese patent announcement numbers CN105703664A, CN105871041A, CN105896709A, CN105703463A, and CN105703665A disclose thermoelectric power generation devices applied to boiler water walls, superheaters, reheaters, economizers, and air preheaters. Flue gas is used as the hot end, and steam (water) or air is used as the cold end to perform thermoelectric power generation. However, considering the current material technology, there is no thermoelectric power generation chip that can withstand such a high temperature (about 400°C to 1300°C).

Moreover, from the perspective of temperature utilization, since the energy gradient of high-temperature flue gas gradually decreases throughout the heat exchange process of the boiler, only the waste heat at the outlet of the air preheater can be called "waste heat". For some small power plants, consider retrofitting Return on investment, low-temperature economizer is not installed in the tail flue of the outlet of the air preheater, so it is considered that if this part of heat can be used, a thermoelectric power generation device can be placed in the tail flue, which can make good use of waste heat and reduce It will have a good market prospect.

Utility model content

The purpose of this utility model is to provide a thermoelectric power generation device that utilizes the waste heat of the flue gas at the tail of the boiler in order to overcome the defects of the above-mentioned prior art, so that the waste heat of the flue gas can be fully utilized, thereby reducing the heat loss of the flue gas to the greatest extent , to maximize the benefits of boiler thermal economy.

The purpose of this utility model can be achieved through the following technical solutions:

A thermoelectric power generation device utilizing waste heat from flue gas at the tail of a boiler. The thermoelectric power generation device is placed vertically in the middle of the tail flue at the outlet of the boiler air preheater. The thermoelectric power generation device includes a thermoelectric power generation module, an inverter, and a A cold source module at one end of the thermoelectric power generation module, the thermoelectric power generation module is connected to the inverter through wires;

The thermoelectric power generation module uses the hot flue gas in the outlet flue of the boiler preheater and the temperature difference of the cold source module to generate electric energy, and transmits it to the inverter through wires.

Preferably, the thermoelectric power generation module is supported and fixed by an upper channel steel and a lower channel steel.

Preferably, the space between the channel steel and the thermoelectric power generation module is filled with insulation cotton for damping vibration and preventing the heat in the flue gas from being transferred to the cold source module.

Preferably, the thermoelectric power generation module includes a heat collector, a radiator, a thermoelectric power generation sheet, bolts and positioning pins;

The thermoelectric power generation sheets are respectively connected to the heat collector and the radiator, the radiator is connected to the cold source module, the bolts pass through the heat collector and the radiator in turn, and the radiator is fixed by positioning pins;

One end of the thermoelectric generation sheet collects heat from the hot flue gas in the tail flue of the boiler preheater outlet through the heat collector as a heat source, and the other end obtains the required cold source from the cold source module through the radiator.

Preferably, the bolt holes on the radiator are larger than the bolt holes on the heat collector.

Preferably, the radiator is arranged between two heat collectors, and fins are provided on the heat collectors.

Preferably, the thermoelectric generation sheets are arranged on both sides.

Preferably, the cold source module includes a cooling water inlet header, a cooling water inlet jellypipe and a cooling water outlet jellypipe, and the cooling water inlet jellypipe, cooling water inlet header and cooling water outlet jellypipe Connected in sequence, the cooling water inlet header and the radiator are arranged close to each other.

Preferably, the cooling water inlet pipe and the cooling water inlet header are respectively connected to the cooling water inlet header through metal hoses.

Preferably, the sides of the radiator, the cooling water inlet jellyfish pipe and the cooling water outlet jellyfish pipe are all wrapped with thermal insulation cotton.

Compared with the prior art, the utility model has the following advantages:

1. Large power generation and small space occupation: the system is placed in the flue behind the air preheater of the power plant boiler, with a large heat flow, allowing many thermoelectric power generation sheets to be arranged; a single power generation module, the thermoelectric power generation sheets are arranged on both sides, which can A large-scale thermoelectric power generation sheet group is integrated, and the area is reduced by half.

2. The device has high reliability: the device is placed in the flue, and the flue vibrates during operation, and the vibration is transmitted to the device. In order to reduce vibration, the power generation module is supported and fixed by two upper and lower channel steels, and insulation cotton is filled between the channel steel and the thermoelectric power generation module, which prevents the heat in the flue gas from being transferred to the radiator while absorbing vibration. At the same time, the cooling water inlet and return water main pipes are connected with the headers by metal hoses, which eliminates the hidden danger of loose joints in the cooling water pipe due to flue vibration and prevents cooling water from leaking into the flue.

3. The heat absorbing area of the heat collector is large, and the heat insulation performance of the radiator and the cooling water circuit is good: each power generation module adopts the design of two heat collectors sandwiching a heat sink, and the fins are processed on the heat collector Compared with the existing device, the heat absorption area is doubled; the heat collector and radiator of each module are connected by bolts. In order to prevent the heat from the heat collector from being transferred to the radiator through the bolts, the bolts on the radiator The diameter of the hole is larger than the diameter of the heat collecting bolt. At the same time, positioning pins are installed on the module to prevent the radiator from moving during operation; the side of the radiator and the surface of the cooling water pipe in the flue are wrapped with thermal insulation cotton to effectively prevent smoke The heat is transferred to the cooling system.

4. Easy installation: Due to the modular structure, each power generation module can be assembled before leaving the factory and completed with heat preservation; each module needs to be spliced on site, and then stuck in the support base and upper fixing bracket.

5. Complete use of waste heat: This power generation module is placed in the tail flue of the boiler air preheater outlet in a thermal power plant (without installing a low-temperature economizer), rather than the heat source in the flue gas process before the boiler preheater, so it is completely It's all about waste heat.

Description of drawings

Figure 1 is a schematic structural diagram of the existing waste heat utilization device arranged before the absorption tower, where A1 is the boiler, A2 is the first preheater, A3 is the electrostatic precipitator, A4 is the induced draft fan, A5 is the chimney, and A6 is the booster Fan, A7 is a low-temperature economizer, A8 is an absorption tower, and A9 is a low-pressure cylinder;

Figure 2 is a schematic structural diagram of the existing waste heat utilization device arranged at the tail of the boiler, where B1 is a dust collector, and B2 is a second preheater;

Fig. 3 is a front structural schematic diagram of the utility model thermoelectric power generation device;

Fig. 4 is a left view structural schematic diagram of a thermoelectric power generation device;

Figure 5(a) is a schematic diagram of the front view of the thermoelectric power generation module;

Figure 5(b) is a schematic side view of the thermoelectric power generation module;

Figure 5(c) is a schematic diagram of a partially enlarged structure of part B of Figure 5(b);

Fig. 5(d) is a partial A-A sectional structural schematic diagram of Fig. 5(a);

Fig. 6 (a) is a schematic structural diagram of the front view of the heat collector of the thermoelectric power generation device;

Figure 6(b) is a schematic diagram of the top view structure of the heat collector of the thermoelectric power generation device;

Figure 7(a) is a schematic structural diagram of the front view of the radiator of the thermoelectric power generation device-1;

Fig. 7(b) is a schematic diagram of the top view structure of the radiator of the thermoelectric power generation device-1;

Fig. 8(a) is a schematic structural diagram of the front view of the radiator of the thermoelectric power generation device-2;

Fig. 8(b) is a top view structure schematic diagram of the radiator of the thermoelectric power generation device-2;

Figure 9 is a general diagram of the system;

1. Tail flue, 2. Lower channel steel, 3. Cooling water inlet header, 4. Thermoelectric power generation module, 5. Metal hose, 6. Cooling water inlet jellyfish pipe, 7. Upper channel steel, 8. Cooling water outlet jellyfish pipe, 9, first connecting rod, 10, second connecting rod, 11, first wire, 12, heat collector, 13, radiator, 14, thermoelectric power generation sheet, 15, bolt, 16, positioning Pin, 17, second wire, 18, inverter, 19, ammeter, 20, electric user, area I is the cold end, area II is the hot end.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of them. . Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

When the power generation device is generating electricity, it is placed vertically in the middle of the tail flue at the outlet of the boiler air preheater. In order to minimize the impact of flue vibration on the thermoelectric power generation system, it is fixed with a support frame and positioning pins, and passed through the boiler exhaust. Smoke waste heat is used as the heat source, and the cooling water of the cold source comes from the closed cooling water system of the power plant (in order to reasonably control the cold end of each thermoelectric power generation sheet to achieve the best cooling effect, so as to maintain a relatively fixed temperature gradient with the flue gas temperature at the hot end , and to ensure the equal distribution of resistance, the system adopts the method of entering water on both sides, collecting water in the middle and then uniformly discharging water) using temperature difference to generate electricity, which is connected in series and parallel and then sent to the inverter with wires to generate 220V AC.

As shown in Figures 3 to 9, the thermoelectric power generation system is placed in the tail flue 1 at the outlet of the boiler air preheater, and the thermoelectric power generation sheets 14 contained in the thermoelectric power generation module 4 pass through the heat collector 12 from the boiler preheater The hot flue gas in the outlet tail flue collects heat at about 150°C as a heat source, and the cold source required by the radiator 13 is taken from the closed cooling water of the power plant through the cooling water inlet pipe 6 at about 10°C. After completing the thermoelectric power generation module After the cooling of the cold end, the cooling water outlet pipe 8 returns to the closed cooling water system of the power plant. The temperature difference generated by the heat source and the cold source is used to generate electricity, connected to the inverter through the first wire 11, and after voltage conversion, 220V alternating current is generated.

The thermoelectric power generation module 4 includes a heat collector 12 , a radiator 13 , a thermoelectric power generation sheet 14 , bolts 15 and positioning pins 16 .

In the connection between the thermoelectric power generation modules and the modules, rely on the first connecting rod 9 and the second connecting rod 10;

In order to prevent the heat from the heat collector 12 from being transmitted to the radiator 13 through bolts 15, the diameter of the bolt opening on the radiator is larger than that of the bolts on the heat collector 12. At the same time, positioning pins 16 are installed on the module to prevent heat dissipation. The radiator moves during operation; the side of the radiator and the surface of the cooling water pipe in the flue are wrapped with thermal insulation cotton, which effectively prevents the heat of the flue gas from being transferred to the cooling water system 3.

In order to avoid flue vibration during boiler operation, and transmit the vibration to the system. In order to reduce vibration, the power generation module 4 is supported and fixed by two upper and lower channel steels, and insulation cotton is filled between the channel steel and the power generation module to prevent the heat in the flue gas from being transferred to the cooler while absorbing vibration. At the same time, metal hoses 5 are used to connect between the cooling water inlet jellypipe 6 and the cooling water inlet header 3, and between the cooling water outlet jellyfish pipe 8 and the cooling water inlet header 3. The hidden danger of loose joints in the cooling water pipeline prevents the cooling water from leaking into the flue.

The radiator provides two structures, as shown in FIG. 7 and FIG. 8 . The cooling water of the radiator shown in Figure 7 achieves the cooling purpose through the holes passing through the radiator, and the cooling water of the radiator shown in Figure 8 achieves the cooling purpose through the water tank passing through the radiator, and at the same time, deflectors are arranged in the water tank.

The above is only a specific embodiment of the utility model, but the scope of protection of the utility model is not limited thereto, and any person familiar with the technical field can easily think of various Equivalent modifications or replacements shall all fall within the protection scope of the present utility model. Therefore, the protection scope of the present utility model should be based on the protection scope of the claims.

Claims (10)

1. A thermoelectric power generation device that utilizes boiler tail flue flue gas waste heat, it is characterized in that the thermoelectric power generation device is vertically placed in the middle part of the tail flue of the boiler air preheater outlet, and the thermoelectric power generation device includes a thermoelectric power generation module ( 4), an inverter (18) and a cold source module installed at one end of the thermoelectric power generation module (4), the thermoelectric power generation module (4) is connected to the inverter (18) by wires; The thermoelectric power generation module (4) utilizes the temperature difference between the hot flue gas in the outlet flue of the boiler preheater and the temperature difference of the cold source module to generate electric energy, and transmits it to the inverter (18) through wires. 2. The thermoelectric power generation device according to claim 1, characterized in that, the thermoelectric power generation module (4) is supported and fixed by an upper channel steel (7) and a lower channel steel (2). 3. The thermoelectric power generation device according to claim 2, characterized in that, the space between the channel steel and the thermoelectric power generation module (4) is filled with insulation cotton for damping vibration and preventing the heat in the flue gas from being transferred to the cold source module . 4. The thermoelectric power generation device according to claim 1, characterized in that, the thermoelectric power generation module (4) comprises a heat collector (12), a radiator (13), a thermoelectric power generation sheet (14), bolts (15 ) and positioning pin (16); The thermoelectric power generation sheets (14) are respectively connected with the heat collector (12) and the radiator (13), the radiator (13) is connected with the cold source module, and the bolts (15) pass through the collector in turn. Heater (12) and radiator (13), radiator is fixed by positioning pin (16) simultaneously; One end of the thermoelectric power generation sheet (14) collects heat from the hot flue gas in the outlet flue of the boiler preheater through the heat collector (12) as a heat source, and the other end obtains the required heat from the cold source module through the radiator (13). cold source. 5. The thermoelectric power generation device according to claim 4, characterized in that, the bolt holes on the radiator (13) are larger than the bolt holes on the heat collector (12). 6. The thermoelectric power generation device according to claim 4, characterized in that, the radiator (13) is arranged between two heat collectors (12), and ribs are provided on the heat collector (12) piece. 7. The thermoelectric power generation device according to claim 4, characterized in that, the thermoelectric power generation sheets (14) are arranged on both sides. 8. The thermoelectric power generation device according to claim 4, characterized in that, the cold source module comprises a cooling water inlet header (3), a cooling water inlet jellyfish pipe (6) and a cooling water outlet jellyfish pipe (8 ), described cooling water inlet jellyfish pipe (6), cooling water inlet water header (3) and cooling water outlet jellyfish pipe (8) are connected successively, and described cooling water inlet water header (3) is connected with radiator (13) Cling to settings. 9. The thermoelectric power generation device according to claim 8, characterized in that, the cooling water inlet pipe (6) and the cooling water inlet header (3) are connected to the cooling water inlet pipe (5) respectively through metal hoses (5). The water header (3) is connected. 10. The thermoelectric power generation device according to claim 8, characterized in that, the sides of the radiator (13), the cooling water inlet jellyfish pipe (6) and the cooling water outlet jellyfish pipe (8) are all wrapped with thermal insulation cotton.